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Re: Question on Anchiornis huxleyi



Fair enough.

Of course, all this is moot if (for instance) Xu et al.'s idea that
archaeopterygids are ALL basal deinonychosaurs, and that oviraptorosaurs
and scansoriopterygids are basal avialians...

On Tue, June 25, 2013 11:04 am, Mark Pauline wrote:
> Yes, sir. You stated everything correctly. I was only worried that, since
> the initial question was about Anchiornis, that some readers could have
> thought that the "this" in Tim's sentence "the morphotype of
> this dromaeosaurid/bird ancestor" was Anchiornis.
>
> Then, I guess, the only question is how we can be certain that the three
> later taxa do share the morphotype of the ancestral paravian as opposed
> to, say, scansoriopterygids. An ancestral state analysis could test this
> hypothesis, but I'm inclined to agree with you that it was probably a lot
> like Eosinopteryx, Aurornis, Anchiornis, and Xiaotingia.
>
>
>
>
> ________________________________
>  From: "Thomas R. Holtz, Jr." <tholtz@umd.edu>
> To: Mark Pauline <markpauline@rocketmail.com>
> Cc: "tijawi@gmail.com" <tijawi@gmail.com>; "dinosaur@usc.edu"
> <dinosaur@usc.edu>
> Sent: Tuesday, June 25, 2013 9:36 AM
> Subject: Re: Question on Anchiornis huxleyi
>
>
> NOTE: I had said, and Tim followed, by saying they had the MORPHOTYPE of
> the ancestor. This is entirely different from saying "were the populations
> from which X is directly derived", i.e., actual ancestors.
>
> There are minor differences between them, yes, but all share a number of
> generalized paravian traits in common at the same body size.
>
> On Mon, June 24, 2013 10:54 pm, Mark Pauline wrote:
> Of course no one is suggesting that Aurornis, Anchiornis, or Xiaotingia
> are
> ancestral to Avialae or Dromaeosauridae, as all of the recent phylogenies
> I am aware
> of show these animals evolving after those nodes. You two must just mean
> that they
> may retain different aspects of that hypothetical ancestor.
>
>
>
>
> ________________________________
> From: Tim Williams <tijawi@gmail.com>
> To: dinosaur@usc.edu
> Sent: Monday, June 24, 2013 8:18 PM
> Subject: Re: Question on Anchiornis huxleyi
>
>
> Thomas R. Holtz, Jr. <tholtz@umd.edu> wrote:
>
>> Ultimately it is far less significant to resolve
>> whether Archaeopteryx &/or Anchiornis &/or Aurornis &/or Xiaotingia &/or
> etc. are
> basal
>> avialians or basal deinonychosaurs or so forth. Instead we should
> recognize that
> we have
>> very likely homed in on the morphotype which gave rise to both the
> dromaeosaurid-line
>> and the bird-line.
>
>
> I couldn't agree more.  Alas, while the morphotype of this
> dromaeosaurid/bird ancestor is being nailed down, the ecotype is still
> open to vigorous debate.  Was this ancestral form terrestrial or
> arboreal?  Did  fly, or not fly?  Was it a predator, or a herbivore,
> or both (omnivore)?
>
>
>
> Thomas R. Holtz, Jr.
> Email: tholtz@umd.edu    Phone: 301-405-4084
> Office: Centreville 1216
> Senior Lecturer, Vertebrate Paleontology
> Dept. of Geology, University of Maryland
> http://www.geol.umd.edu/~tholtz/
> Fax: 301-314-9661
>
> Faculty Director, Science & Global Change Program, College Park Scholars
> http://www.geol.umd.edu/sgc
> Fax: 301-314-9843
>
> Mailing Address:    Thomas R. Holtz, Jr.
>             Department of Geology
>             Building 237, Room 1117
>             University of Maryland
>             College Park, MD 20742 USA


Thomas R. Holtz, Jr.
Email: tholtz@umd.edu   Phone: 301-405-4084
Office: Centreville 1216
Senior Lecturer, Vertebrate Paleontology
Dept. of Geology, University of Maryland
http://www.geol.umd.edu/~tholtz/
Fax: 301-314-9661

Faculty Director, Science & Global Change Program, College Park Scholars
http://www.geol.umd.edu/sgc
Fax: 301-314-9843

Mailing Address:        Thomas R. Holtz, Jr.
                        Department of Geology
                        Building 237, Room 1117
                        University of Maryland
                        College Park, MD 20742 USA